This invention relates to a method and apparatus for providing voice path assurance (VPA) testing in a packet network such as an Internet Protocol (IP) network. More specifically, the invention relates to a voice path assurance (VPA) testing technique that is initiated on the terminating side of a logical connection through an IP network. The technique of the present invention is used to verify connectivity and performance—during a call set-up procedure—between the terminating point and the originating point of a logical connection through the IP network.
While the invention is particularly directed to the art of voice path assurance testing in an IP network, and will be thus described with specific reference thereto, it will be appreciated that the invention may have usefulness in other fields and applications. For example, the invention may be used in any packet network where it is advantageous to conduct testing from the terminating side of a connection. Moreover, the invention may be used in environments wherein it is advantageous to conduct testing prior to setting up packet streams that are delay/loss sensitive, such as streaming video.
By way of background, establishing a voice path in many types of networks is relatively straightforward. As such, testing for voice path assurance is likewise straightforward and reliable. For example, in a time-division multiplexed (TDM) network, a voice path is established using physical, e.g. semi-permanent, connections between endpoints on the network. As such, these physical connections between endpoints can be continuously monitored, during both idle intervals and busy intervals, to ensure the integrity and performance of the connection. In addition, a provisionable per call voice path assurance test (i.e. continuity test) is typically implemented to supplement the continuous monitoring of the physical connection. The originating endpoint of the voice path initiates this continuity test between itself and the terminating endpoint for some or all of the calls carried on the connection.
Such testing could be applied to a packet network, but it has drawbacks that would render such testing impracticable. For example, in packet networks such as IP networks, there are no physical (e.g. semi-permanent) connections between the originating and terminating endpoints. Connections between endpoints in a packet network such as an IP network are logical. Sockets are provided at each endpoint to allow for packets to be communicated therebetween; however, no physical or semi-permanent path is maintained. Therefore, continuous monitoring to ensure connectivity is not practically possible. As a consequence, there is some probability that attempts to establish new logical connections across an IP network may fail or may result in low quality logical connections. Of course, neither outcome is desirable.
The present invention contemplates a new voice path assurance (VPA) testing technique that resolves the above-referenced difficulties and others.